Syrian troops have attacked two towns north of the capital Damascus, as they continue a crackdown against anti-government protests, reports say.
Witnesses said the troops, backed by tanks and helicopters, surrounded Rastan and Talbisa early on Sunday and searched houses for protesters.
Anti-government activists said five people were killed and many wounded.
Human rights groups say more than 1,000 people have been killed in Syria since the uprising began in March.
Syria has banned foreign journalists, making it difficult to verify eyewitness accounts. Syrian authorities insist they are pursuing "armed terrorist gangs".
The two towns attacked on Sunday are on the main road north out of Homs, the site of some of the largest demonstrations in recent weeks.
Tanks encircled Rastan and troops began firing heavy machine-guns in the streets of the town, an eyewitness told Reuters news agency.
Scores of tanks were used, with helicopters flying overhead - as security forces broke into houses arresting people.
Residents of both towns said water, electricity and communications were cut early on Sunday as the troops and tanks moved in.
The authorities have said nothing about the reported attacks, says the BBC's Jim Muir in neighbouring Lebanon.
Both Rastan and Talbisa have been caught up in the protests since March, and dissent has continued there despite harsh repression, says our correspondent.
The towns were the scene of large protests demanding the resignation of President Bashar al-Assad.
Opposition sources report ongoing demonstrations and vigils, often at night, in many parts of the country.
They also say security forces have continued to hunt down and detain activists in towns and cities throughout Syria.